Electric radiant range



May 23, 1933. L. LEBAU ELECTRIC RADIANT RANGE Filed Jan. 25, 1952 2Sheets-Sheet l INVENTOR.

BY ZaZA M A TTURNEYS- May 23, 1933. L. LEBAU 1,910,700

ELECTRIC RADIANT RANGE Filed Jan. 25, 1932 2 Sheets-Sheet 2 IN VENTOR.

A TTORNE Y8.

Patented May 23, 1933 LOUIS LEBAU, 0F PITTSBURGH, PENNSYLVANIA ELECTRICRADIANT RANGE Application filed January 25, 1932.

This invention relates to improvements in electric radiant ranges orstoves especially adapted for cooking purposes.

Heretofore, so far asI am aware, electric ranges or stoves have had aresistor element carried by a base plate formed of china or otherbrittle material, the latter having the resistor elements eitherembedded therein completely, or, in some instances, having a coiledresistor element loosely held in open grooves below the level of theupper surface of said plate.

In such constructions, the cooking uten sil is placed directly on thechina base plate in order to obtain sufiicient heat, and this frequentlyresults in fracturing the plate, due to impact. Liquids are frequentlyspilled during the process of cooking, and upon striking the hot chinabase plate, cause the same to disintegrate by producing small crackstherein.

Further in the case of the open top plate having the coiled resistorelement loosely held in open grooves, there is danger of short circuitsfrom spilled liquids. The contact of the liquid with the hot resistorelement may cause the latter to warp or buckle into contact with a metalutensil or the metal of the range, causing current to flow and possiblyresult in injury.

VVith'units of the above character, it has been dangerous as well asimpractical to employ metal grids or gratings similar to those used in;gas stoves, since the grating would necessarily have to be placed atsuch a distance therefrom as to render the unit incitic-ient.

- It is a prime object of my invention to providean electric range orstove construction havingan electric heating unit therein, ineluding aresistor element carried by a heatreflecting plate or block, anopen-work retractory radiant member superimposed thereon for securelyretaining said resistor element on the plate, and a metallic grid orgrating member extending over the radiant member in close proximity tothe resistor element for supporting cooking utensils thereabove.

A further object is to provide cooperating Serial No. 588,517.

passages in the heat-reflecting blocks for ad initting air to theresistor element, for heating the air and moving the same upwardly toassist the transfer of heat for the purpose intended, said passages alsofunctioning in connection with a slotted resistor elementand theopen-work radiant member to permit ready drainage of fluids through theheating unit.

Additional objects and advantages will be come apparent from thefollowing descrip tion taken in connection with the accompanyingdrawings, wherein:

Fig. 1 is a perspective view of an electric range embodying myinvention;

Fig. 2, an enlarged vertical section taken on the line II-II of Fig. 1;

F ig. 3, a top plan view of the heat-reflecting plate;

Fig. 4, a bottom plan View of the radiant member, particularly showingthe electric resistor element positioned therein; and i Fig. :5, abottom plan View of the metal grid or grating.

Referring to the drawings, the range or stove, somewhat diagrammaticallyshown in Fig. 1, consists of a body portion 2 constructed in theconventional manner of sheet metal or the like, and has a top 3positioned thereon. The top may be formed with one or more openings attherein for receiving the heating units, a single unit range beingillustrated in Fig. 1.

It will be understood that various designs of ranges or stoves may beemployed in connection with my invention to provide an efficient andattractive assembly.

The heating unit is of the electric radiant type shown in my pendingapplication Serial No. 435.468, filed March 13, 1930, and in mycompanion application filed herewith, Serial No. 588,518. Said unitincludes a heat-reflecting plate or block 5 of suitable material capableof reflecting heat and having insulating properties.

For example, the plate or block may be formed of fire clay prepared withsawdust or the like and kiln fired to burn out the sawdust and form amore or less porous body. Such material, when formed into a plate orblock of substantial thickness, will properly insulate the range orstove and will provide a face or surface which, when subjected to theextreme heat of an electric resistor element, will attain a hightemperature and glow with a red color. The applied heat w ll penetratethe plate or block but a slight distance'due to the insulating qualitiesof the material. The hot surface area of the plate acts as a reflectorto reflect and radiate heat therefrom.

As illustrated, the reflector plate comprises a body of rectangularshape having the top or heat-reflecting face thereof formed with arectangular depression or recess 6. Positioned in the depression orrecess, I provide a lurality of spaced-apart parallel horizontal yextending ribs or projecting elements 7, preferably formed integral withthe bod i Elements 7, as shown and as preferred, are narrow in width andare arranged in groups of three, each group consisting of outer ribs aand a central rib I), and are spaced to produce horizontally extendingair passages 8. The groups are also spaced apart to provide interveninghorizontal spaces or grooves 9 for a purpose hereinafter described. Aseries of air ducts or openings 10 are also provided and extendvertically through the plate 5 from the communicating air passages 8.

In connection with such a back wall or reflector plate, I prefer toemploy a flat resistor element formed of thin metal strips 11 havingnarrow spaced-apart slots 12 cut therein alternately from the edges ofsaid strips to provide a sinuous path for the current. The said strips11 are of substantially the same width as thedistance between the outerribs (1 of each group hereinbefore described, and are positioned thereonto lie flatwise in'a horizontal plane.

When the resistor strips 11 are thus positioned on the ribs 7, one stripfor each group of three ribs, adjacent strips are electrically connectedby portions 13, either at the upper or lower portions of the ribs. Forthis purpose, the end portions of the outer ribs a of adjacent groupsare cut away, as at 14, to accommodate the connecting portions 13. Thecentral ribs 1) of each group serve to support the thin flat resistorelements and prevent buckling or distortion.

Superimposed upon the block or reflector plate 5v is an open-workradiant member 15; this radiant member is formed of refractory clay orthe like and includes irregular connecting face portions 16 separated byopenings 17 worked into an attractive design. The radiant membersubstantially conforms in shape and size to the depression 6 of theplate 5, and has a downwardly depending mar inal flange 18 for entrancein the outer portion of said depression.

Radiant member 15 is provided with spaced-apart vertically extendingribs 19 adapted to be positioned in the spaces or grooves 9 betweenadjacent groups of reflector plate ribs 7, as particu arly shown by Fi2. Said ribs 19 are cut away at their en portions, as at 20, to span theconnecting portions 13 of the resistor strips.

The under face of the radiant member 15 contacts with the resistorelements or strips 11 to securely maintain the same flat against theirsupporting ribs 7. The ribs 19 and vertical portion of the marginalflange 18 cooperate with grooves 8 and the depression 6 to preventlateral movement or disengagenient of the resistor strips 11.

Positioned directly on the radiant'member 15 with its under surfacecontacting the upper surface of said radiant member, I pro vide a metalgrid or grating member 21 preferably formed of cast iron or the like,consistin of a marginal frame portion 22 and radia ly extendingspaced-apart members 23 arranged to form a grating for supportingcooking utensils thereon. The said grid is relatively thin and is spacedbut a slight distance above the electric resistor elements 11, thusproviding for the efficient heating of a utensil or the like placed onthe grid member.

Screws or bolts 24 are passed through the grid member and the reflectorplate 5 to secure said member thereto and securely hold the radiantmember 15 in position on the resistor elements. Downwardly extendingprojections or feet are provided on the grid member for extending andresting in the depression or recess 6 in the top of the reflector block.

Depending ribs 26 are also provided on the under side of the grid member21 for embracing and securing the radiant member 15 against lateralmovement.

The heating unit is supported as a whole in the opening 4 of the rangetop 3 so that the upper surfaces of the grid member 21 and said range tolie in the same horizontal plane. For t is purpose I provide anglemembers 27 embracing opposite lower edges of the reflector plate. Saidangle members may be secured to the said plate by bolts 01' screws 25 asshown or in any suitable manner.

The angles 27 and hence the heating unit is supported by cross anglemembers 28 becured to the range body as at 29. Bolts or other means maybe em loyed in securing said unit in position on t e angles 28.

The body of the range is provided, preferably at its rear wall, with aseries of openings 30 for the purpose of admitting air to the interiorthereof and to the heating unit. For this purpose the interior of therange is sufiiciently large to provide an air chamber 31 below andaround the heating unit to permit the air to circulate from the openings30 upwardly through the said unit.

In the operation of my invention, the terminals of the resistor elementare connected with a source of electrical energy in any suitable mannerthrough a control switch indicated at 32. When the switch is turned on,the resistor element 11 becomes heated and imparts heat to the reflectorplate 5 as described.

Due to the open slots 12 in the resistor element, the air passages 8 andthe vertical ducts or openings 10 in the reflector plate, an upwardcirculation of air is induced by the heatof the element, the air drawninto chamber 31 through the openings 30 in the body of the range passesupwardly through the chamber. The air in passing through the resistorelement becomes heated and passes upwardly through the open-work radiantand grid members where its heat may be utilized for cooking purposes.

In the event that fluids are spilled on the range and the heating unit,they will be speedily drained through the radiant, resistor andreflector plate to the chamber 31 therebelow where they may be collectedand removed by means of a tray The resistor element is securely heldbetween the radiant member and reflector plate, and therefore it isimpossible for it to become warped or distorted.

With my construction maximum current may be initially applied andcontinued for a short time or until the heating surface of the reflectorplate reaches a red heat after which the current may be considerablyreduced and continued at the reduced Value without a reduction of theheating medium to a point below satisfactory cooking temperature, thusproviding an electric range that may be operated at a minimum cost.

What I claim is:

1. An electric radiant range including a heating unit including areflector plate having an air passage in the top thereof and acommunicating opening extending through the plate, an electric resistorelement dis= posed on the plate adjacent the air passage, an open-workrefractory radiant member superimposed on the plate and over theresistor element, and a grid member positioned over said radiant member.

2. An electric radiant range including a heating unit comprising areflector plate having an air passage in the top thereof and acommunicating opening extending through the plate, an electric resistorelement on the plate adjacent the. air passage, an open-work refractoryradiant member superimposed on the plate and over the resistor element,and a metal grid member positioned over said radiant member.

3. An electric radiant range including a heating unit comprising areflector plate hav ing an air passage in the top thereof and acommunicating opening extending through the plate, an electric resistorelement on the plate adjacent the air passage, an open-Work refractoryradiant member su aerimposed on the plate and over the resistor element,and a metal grid member positioned over said radiant member and securedto the reflector plate.

4. An electric radiant range having an air chamber and an air openingtherein, a range top having an opening therein, a heating unitpositioned in the said top opening and including a reflector platehaving air passages therethrough communicating with the air chamber, aflat slotted electric resistor element on said plate and extending oversaid air passages, an open-work refractory radiant member superimposedon the plate and engaging said resistor element, and a metal grid memberdisposed over said resistor element and spaced therefrom by the radiantmember.

5. An electric radiant range having a top formed with an openingtherein, a heating unit positioned in said opening and including areflector plate having air passages there through, a flat slottedelectric resistor ele ment on said plate and extending over said airpassages, an open-work refractory radiant member superimposed on theplate and engaging said resistor element, and a metal grid memberpositioned on said radiant memher with its upper surface in alinementwith the upper surface of the said range top.

(3. An electric radiant range comp-rising a hollow body having an airchamber and an air opening therein, an apertured range top, a heatingunit for the range including a reflector plate having air passagestherethrough connnunicating with said air chamber, a fiat slottedelectric resistor element on said plate and extending over said said airpassages, an open-work refractory radiant member superimposed on theplate and engaging said resistor element, a metal grid member on saidradiant member. and means in the air chamher for supporting the heatingunit.

In testimony whereof I afiix my signature.

LOUIS LEBAU.

